In the construction of building structures, it is frequently necessary to support a concrete structure from another structure (concrete or otherwise). It is also frequently necessary to support heavy objects on or from concrete structures. For instance, in building constructions it may be necessary to support heavy pipes for fire suppression sprinkler systems from concrete ceilings or walls. Further, in certain industrial buildings, it may also be necessary to support heavy equipment on concrete floors, ceilings or walls. In certain industrial buildings, equipment may need to be slidably supported on a ceiling, wall or floor so that it can be moved along a defined path.
In order to support such heavy objects, the load should be supported from deep within the concrete structure so that the load is transferred throughout a large volume of the concrete. The larger the volume of concrete supporting the object, the heavier an object which can be supported without damaging the concrete structure. Accordingly, it is known to provide a primary support member, such as a hanger, nut or track, on the surface of the concrete. The object to be supported can be attached to the primary support member by means of a mating hanger or bolt. In order to transfer the load deep within the concrete, the bolt, hanger, track or other primary support member is attached to a secondary support member, such as a lug or a series of wires, buried deep within the concrete. Since the primary support member is on the surface of the concrete, it receives substantially no support from the concrete, except through the secondary support member which is buried within the concrete. Accordingly, the primary support member must be a heavy duty support member which is securely attached to the secondary support member, which also should be heavy duty.
Accordingly, both the primary and secondary support members must be heavy duty support members, adding significant cost.
In a situation where a heavy piece of equipment must be slidably supported in a track on a concrete structure, the track must be supported in the concrete by lugs or other secondary support members at closely spaced intervals. That is, since the heavy load may be positioned anywhere within the track, the track must be strongly supported over its entire length. There cannot be a significant distance between secondary support members for the track since, if the load is supported from a point in the track which is too distant from a secondary support lug, the load will not be effectively transferred from the track to a lug. Accordingly, the track may bend or be otherwise deformed under the weight of the load.
Further, it is frequently necessary to very precisely position a secondary support member in the concrete so that its corresponding primary support member will mate properly with the attachment hardware of another concrete structure or a piece of equipment to which it is to be attached. Accordingly, it is important to assure the proper placement of secondary support members since they are buried within the concrete and are generally immoveable after the concrete has set.
Patent application Ser. No. 08/369,449 discloses an apparatus comprising a concrete insert which is placed within a concrete wall which can support a support member within the wall and which achieves many of the goals discussed above. FIGS. 1A and 1B illustrate the apparatus disclosed in that application. A slotted insert is embedded within a concrete structure. Particularly, the slotted insert is a plastic extrusion molded insert elongated in a first direction and having a T-shaped cross-section perpendicular to the first direction. The insert is formed of a wall which defines an interior volume of the insert which also is T-shaped. The interior volume of the insert, therefore, defines an elongated channel extending in the first direction with the cross-section of the channel comprising two contiguous volumes, one being short and wide (the horizontal top of the T) and the other being long and thin (the vertical leg of the T).
Prior to assembly, the opposite ends of the channel are open so that a nut can be inserted from either end into the short and wide transverse portion of the channel. The two volumes are dimensioned so that the nut can fit horizontally within the transverse portion of the contiguous volume but cannot, in its horizontal orientation, fit through the vertical portion of the volume. Further, the nut preferably has a square perimeter, the sides of which are substantially equal in length to the width of the transverse portion of the volume, so that, once the nut is placed within the insert, it cannot be rotated. Once the nut is placed in the insert, end caps are attached to the open ends of the insert by glue or other means.
The insert is then positioned in the form within which the concrete structure will be poured and set such that when the concrete is poured, the base of the T-shaped insert (i.e., the bottom surface of the longitudinal leg) is coplanar with a surface of the concrete, but the remainder of the insert is embedded within the concrete. After the concrete has set, the wall of the insert which defines the base surface of the T is removed.
When it is necessary to support an object on the concrete structure, a bolt attached to the other structure or equipment can be inserted into and secured to the nut which is in the insert embedded within the concrete. Accordingly, the load is transferred, through the nut, deep within the concrete.
The two end caps have extensions protruding from the transverse portion of the T to form supporting feet. During fabrication of the concrete structure, the assembled insert, with the end caps in place, is positioned within the form within which the concrete structure is to be formed with the feet of the end caps resting on an inner surface of the form (i.e., the T is upside down). The insert, thus, is actually supported off of and above the inner surface of the form by the feet of the end caps. Accordingly, when the concrete is poured into the form, the transverse leg of the T will not be resting on the bottom surface of the form, but will instead be supported by the feet above the form a distance equal to the height of the feet. Thus, when the concrete is set, the top of the transverse portion of the insert will be embedded within the concrete rather than coplanar with a surface of the concrete. The height of the feet can be selected relative to the desired thickness of the concrete structure and the height of the insert to assure that the base of the T-shaped insert, within which the opening exists, will be coplanar with the opposite surface of the concrete structure. The feet prevent the bottom surface of the insert from being coplanar with the surface of the concrete when set. It is undesirable to have any interior volume of the insert unnecessarily coplanar with or close to the surface of the concrete structure within which it is embedded because it weakens the concrete structure overall.
Accordingly, it is an object of the present invention to provide a low-cost support member for concrete structures.
It is another object of the present invention to provide a support member for a concrete structure which is set deep within the concrete in order to supply sufficient load transfer to the concrete, yet still be moveable.
It is a further object of the present invention to provide a support member for a concrete structure which further transfers load to steel reinforcement bars embedded in the concrete.
It is yet one more object of the present invention to provide a slidable support member which transfers load deep within the concrete over the entire length of the slidable support member.
It is yet another object of the present invention to provide a support member in an insert embedded within a concrete structure in which the support member can have a height as great as the thickness of the concrete structure, thus maximizing the volume of concrete supporting the load, while minimizing the interior volume of the insert which is coplanar or close to the surface of the concrete.
It is yet a further object of the present invention to provide a support member embedded within a concrete structure which transfers the load supported by a support member within the insert to a greater volume of concrete than is known in the prior art.